3D Structure Determination of an Unstable Transient Enzyme Intermediate by Paramagnetic NMR Spectroscopy
作者:Jia-Liang Chen、Xiao Wang、Feng Yang、Chan Cao、Gottfried Otting、Xun-Cheng Su
DOI:10.1002/anie.201606223
日期:2016.10.24
conformational plasticity, but structural information on transient intermediates is difficult to obtain. We show that the three‐dimensional (3D) structure of an unstable, low‐abundance enzymatic intermediate can be determined by nuclear magnetic resonance (NMR) spectroscopy. The approach is demonstrated for Staphylococcus aureus sortase A (SrtA), which is an established drug target and biotechnological reagent
酶催化依赖于构象可塑性,但很难获得有关瞬态中间体的结构信息。我们表明,可以通过核磁共振(NMR)光谱确定不稳定,低丰度酶促中间体的三维(3D)结构。该方法已针对金黄色葡萄球菌进行了证明分选酶A(SrtA),它是既定的药物靶标和生物技术试剂。SrtA是将底物肽的酰胺键转化为硫酯的转肽酶。通过测量由不与活性位点残基Cys184反应的位点特异性半胱氨酸反应性顺磁性标签产生的伪接触位移(PCS),收集了足够数量的约束物来确定SrtA不稳定硫酯中间体的3D结构,从而在非平衡条件下仅作为次要物种存在。3D结构揭示了保护硫酯中间体免于水解的结构变化。